This invention relates to a cap device for sealing a mouthpiece of a container such as a bag-in-box which is required to have sterilizing ability and methods of sealing a mouthpiece portion of the container by utilizing the cap device and opening the same.
There is known a container which is required to be hermetically sealed and, as one example of the container of this character, is known so-called a bag-in-box of the type in which a foldable plastic bag container is accommodated in a corrugated fiberboard box for an outer package so as to utilize the box as a container suitable for conveying and reserving liquid content.
It is important to keep the sterilized condition for drink liquid and chemical liquid in a case where such liquids are fed into the bag-in-box of the character described above. In addition, for such a bag-in-box, it is also required to be easily used and handled. Accordingly, the bag-in-box container and the cap device are subjected to sterilizing treatment (for example, irradiation of .gamma.-ray) beforehand. Many improvements for the structure of the cap device have been made for this purpose. However, almost all existing cap devices are constructed as single unit caps.
In the prior technique, in the actual usage of the bag-in-box container which is filled up with liquid under sterilized condition, a cap is manually removed and a mouth portion of the bag-in-box is then connected to a take-out jig such as a connector to take out the liquid in the bag-in-box. Accordingly, a mouthpiece of the bag-in-box container is temporarily directly exposed to an outer atmosphere at a time of being connected to the connector and there may cause a case where the outer atmosphere is intruded into the bag-in-box container or air of a head space in the container is flown out.
In view of the maintenance of the sterilization of the bag-in-box, it is not desired that the mouth portion is directly exposed to the outer atmosphere even in temporarily and many technical attempts have been tried to eliminate this problem.
A certain conventional cap device for the container such as bag-in-box is provided with a function as a connector. Such cap device is provided with a connector member to which a coupling member is connected to thereby form a dispenser means (external connection line) for optionally taking out the content in the bag-in-box. For the bag-in-box container of this type, it is also required to be provided with the sterilization maintaining property.
However, the connector member of the mouthpiece of the conventional cap device is, in general, sealed by one valve member. Therefore, when the dispenser means is assembled by connecting the coupling member to the connector member as described above, the content in the bag-in-box is always communicated with contaminated portions of the connector member and the coupling member.
The insufficient control of the dispenser means to microorganisms may be resulted, in an adverse case, in the degradation of the content or food poisoning for a person.